This disclosure relates to metal ester polymers, methods of manufacture, and uses thereof, for example as dielectric insulating materials.
Dielectric insulating materials used in applications such as capacitors, field effect transistors, electromechanical systems and photovoltaics desirably have a large dielectric constant (Dk), a large energy band gap, low loss, and low conductivity. It is a further advantage if the materials are light-weight and readily manufactured. Current commercially available insulating materials include ceramics and certain polymers. Commercial polymers for use as dielectric materials include polyolefins, due to the favorably low conductivity of these materials. Compared to dielectric ceramics, these polymers meet industry needs for lighter weight and easier processing. On the other hand, such polymers are known to have either a low dielectric constant or low band gap, or both, making them less suitable for the target applications.
To increase the dielectric constant of insulating polymers, two methods have been used. One approach includes incorporating a larger permanent dipole moment within the polymer backbone to increase orientational polarization. The approach has been applied to polyvinyldiene fluoride (PVDF) since it has a large band gap (about 6 eV). A second approach has been the addition of inorganic, high dielectric constant fillers to introduce interfacial polarization between the filler particles and polymer. However, both of these methods have limitations. Although PVDF has a dielectric constant of greater than 10, it is ferroelectric in nature and suffers from large dielectric losses. Filled insulating polymers require large volumes of particles to reach percolation of the dielectric constant and, as a result, can suffer from a decrease in the dielectric breakdown field.
There accordingly remains a need in the art for polymeric materials that exhibit a high dielectric constant, high energy band gap, low loss, and low conductivity, properties that make these polymeric materials suitable for use in applications including high energy density capacitors, printed circuits, and gate dielectrics for transistors.